The present invention relates to a backlit photodiode array, and more particularly, to a backlit photodiode array formed on a silicon on insulator (SOI) substrate having backside contacts.
A photon detector or photodetector (also called a photodiode) is a semiconductor device that converts radiant power or light directly into electrical current. Positive-intrinsic-negative (PIN) diodes or PIN photodiodes are generally known in the art. A PIN/NIP diode is a form of photodetector.
A PIN diode is a type of photodiode with a large, neutrally doped intrinsic region sandwiched between p-doped and n-doped semiconducting regions. The PIN diode's name comes from the layering of the materials positive, intrinsic, negative (PIN). A PIN diode typically exhibits an increase in its electrical conductivity as a function of the intensity, wavelength, and/or modulation rate of the incident radiation.
A PIN diode also operates as a variable resistor at radiofrequency (RF) and microwave frequencies. The resistance value of the PIN diode is determined only by the forward biased direct current (DC) current. At high RF frequencies when a PIN diode is at zero or reverse bias, it appears as a parallel plate capacitor, essentially independent of reverse voltage.
Photoconductor arrays are groups of a plurality of photodetectors, such as PIN/NIP diodes, arranged together on a substrate or wafer.
It is desirable to provide a backlit photodiode array formed on a silicon on insulator (SOI) substrate having backside contacts.